Checking for permutation of a palindrome in JavaScript

We are required to write a JavaScript function that takes in a string as the first and the only argument.

The task of our function is to check whether any rearrangement in the characters of the string results into a palindrome string or not. If yes, then our function should return true, false otherwise.

For example −

If the input string is −

const str = 'amadm';

Then the output should be −

const output = true;

because the string can be rearranged to form 'madam' which is a palindrome string.

Example

The code for this will be −

const str = 'amadm';
const canFormPalindrome = (str = '') => {
   const hash = {};
   let count = 0;
   for (let i = 0; i < str.length; i++) {
      let c = str[i];
      if(c === ' '){
         continue;
      };
      if(hash[c]){
         delete hash[c];
      }else{
         hash[c] = true;
      };
      count++;
   };
   if(count % 2 === 0){
      return Object.keys(hash).length === 0;
   }else{
      return Object.keys(hash).length === 1;
   };
};
console.log(canFormPalindrome(str));

Output

And the output in the console will be −

true